inability of the mind

One of my greatest inabilities is instability of mind. What seems correct at one moment seems the exact opposite at the very next instance. Ultimately this has become a cause of concern. Such a fluctuating mind will give no scope for decision making. Without the ability to take appropriate decisions at the right time, a man can never be successful. The very foundation of success lies on decision making. Now that I know about my inability how to get rid of it ? no answers so far... ? I guess its better to stick on to a decision irrespective of the consequences. All the thinking has to be done before the decision has been taken and not at a later point in time.